In order to determine the suspension travel or height levels the prior art discloses measuring, in the vicinity of the wheels, a length of a dimension between the chassis and the vehicle body or the change in a position of a measuring point. For example, four-wheeled vehicles always have one such measuring sensor per wheel or three such measuring sensors, these being designated as height-level sensors in the following.
However, height-level sensors are relatively expensive and subject to significant stresses during their deployment in a motor vehicle. This is due in particular to adverse mechanical effects e.g. from particles and stones which are swirled up into the region between wheels and vehicle body during travel, and from humidity and temperature fluctuations.